Apparatus and System for Refrigerant Compressor with Liquid-Suction Heat Exchanger

ABSTRACT

There is provided a refrigeration apparatus ( 100 ). The refrigeration apparatus ( 100 ) includes a liquid suction heat exchanger (LSHX) ( 110 ) and a compressor ( 120 ). The LSHX ( 110 ) and the compressor ( 120 ) are formed as an integral module ( 150 ). Disclosed combinations include tandem compressors ( 151, 152 ) and multiple integral module configurations ( 185, 186 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a refrigerant system. Moreparticularly, the present invention relates to an integral moduleincluding a refrigerant compressor and a liquid-suction heat exchanger.

2. Description of the Related Art

In many refrigerant systems, performance enhancement demands dictateimplementation of additional components for a capacity and/or efficiencyboost. Employment of a liquid-suction heat exchanger (LSHX) is one ofthe choices to satisfy such requirements in many operating environments.Generally, a LSHX provides for extra subcooling of a liquid refrigerantleaving a condenser by superheating of a refrigerant vapor entering acompressor suction port (or ports). Accordingly, although refrigerantvapor density entering the compressor is reduced, the enthalpy boostresulting from subcooling of the liquid refrigerant often leads to anoverall refrigerant system performance augmentation. Additionally,employment of a LSHX helps in reducing the possibility and severity ofcompressor flooding that could cause permanent damage to the internalcompressor components. In particular, a LSHX can be useful inapplications with long suction lines leading to the compressor, whereinadditional preheating of the refrigerant in the LSHX would take place topotentially eliminate or reduce flooding. Further, a LSHX assuressubcooling conditions at the entrance to the expansion device andconsequently eliminates its malfunctioning.

However, inclusion of a LSHX increases refrigerant system costs to thepoint that the benefits obtained by the LSHX performance enhancementbecome economically prohibitive. On the other hand, in determiningcosts, it is a common practice to consider “applied” costs, whichinclude both the component costs (i.e., the costs of the individual LSHXand compressor components), as well as the cost of on-site labor andinstallation and other associated costs to assemble these componentsinto a working system at the factory or in the field. In particular,these labor and installation costs can be a disincentive in using theLSHX in a refrigerant system and should be carefully evaluated.

Therefore, there is a need for a refrigerant apparatus and system thathas a LSHX that does not have the same level of labor and associatedcosts as conventional LSHX/compressor apparatuses and systems.

SUMMARY OF THE INVENTION

In one embodiment, the present invention provides for a refrigerantapparatus that incorporates a liquid suction heat exchanger (LSHX) and acompressor, and the LSHX and the compressor are formed as an integralmodule.

In another embodiment, the present invention provides for a refrigerantsystem with the integral module that incorporates a compressor and aLSHX secured to the compressor.

In still yet another embodiment, the present invention provides for anintegral module preferably positioned on a common base and including acompression system and a single LSHX, wherein the compression systemconsists of a plurality of compressors connected in tandem all connectedto a single LSHX.

In another embodiment, the present invention provides for an integralmodule, preferably positioned on a common base and consisting of aplurality of compressors and a plurality of LSHXs, each compressorconnected to its own LSHX.

It is an object of the present invention to provide for a modularassembly of a LSHX and compressor, thereby reducing installation costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a single, integral module comprising a LSHX connected to aside of a compressor.

FIG. 2 is a single, integral module comprising a LSHX connected to a topof a compressor.

FIG. 3 is a single, integral module comprising a LSHX connected to abottom of a compressor.

FIG. 4 is a single, integral module comprising a plurality ofcompressors connected to a single LSHX.

FIG. 5 is an integral module comprising a plurality of compressors and aplurality of LSHX's, each compressor connected to its own LSHX.

FIG. 6 illustrates a refrigerant system that has an integral modulecomprising a compressor and LSHX.

DESCRIPTION OF THE INVENTION

Referring to the drawings and, in particular, FIG. 1, there isillustrated an integral module generally expressed by reference number150. Integral module 150 includes a LSHX 110 connected to a compressor120. An integral module can be generally defined as a subassembly of atleast two closely connected non-removable components that havedistinctly defined interfaces to the rest of the system. LSHX 110 andcompressor 120 are connected so as to be integral module 150 and arepermanently secured to each other during manufacturing. Within integralmodule 150, inlet 115 of LSHX 110 for refrigerant vapor leaving anevaporator is part of a vapor refrigerant interface. A discharge port135 of compressor 120 is another part of the vapor refrigerantinterface. LSHX 110 has two connections for a liquid refrigerantinterface as well. One is connection 130 for liquid refrigerant leavinga condenser and the other is connection 131 for a line leading to anexpansion device.

Compressor 120 has suction port 125 and discharge port 135. Suction port125 is located at compressor 120 and downstream of LSHX 110. Dischargeport 135 represents another vapor refrigerant interface of integralmodule 150 for compressed refrigerant vapor delivered by the compressor120 to a discharge line.

In one embodiment, shown in FIG. 1, suction port 125 is associated witha single unitary pipe 127. Single unitary pipe 127 is connected to bothLSHX 110 and compressor 120 of integral module 150. Single unitary pipe127 is secured to both an outlet of LSHX 110 and suction port 125 ofcompressor 120.

As mentioned above, integral module 150 has two well-defined interfaces.The vapor refrigerant interface includes two connections, inlet 115 ofLSHX 110 and discharge port 135 of compressor 120, and a liquidrefrigerant interface, which includes connections 130 and 131 to anoutlet of a condenser and inlet of an expansion device respectively. Useof integral module 150 allows employment of a modular design philosophyto reduce applied compressor costs (i.e., costs in installation,storage, shipping, etc.), in systems where the use of LSHX 110 isdemanded by the performance requirements. Additionally, reduction of anumber of connections and component mismatch reduces potentialreliability problems.

By having LSHX 110 and compressor 120 manufactured, marketed and sold asintegral module 150, manufacturing costs and complexities can bereduced. This is because, among other things, various module interfaces,such as vapor refrigerant interfaces (inlet 115 of LSHX 110 anddischarge port 135 of compressor 120) and liquid refrigerant interfaces(connections 130 and 131 to an outlet of a condenser and inlet of anexpansion device respectively) can be precisely defined, since there areno further components to be inserted between LSHX 110 and compressor120. Implementation of these precisely defined interfaces typicallyreduces installation costs. In FIG. 1, LSHX 110 is positioned to a sideof compressor 120. In a further embodiment, LSHX 110 and compressor 120are secured (e.g., bolted) together.

In FIGS. 2 and 3, other examples of connections between LSHX 110 andcompressor 120 are illustrated. In FIG. 2, LSHX 110 is positioned on atop of compressor 120. LSHX 110 is connected to compressor 120 throughsingle unitary pipe 127. LSHX 110 is secured to compressor 120 andsupported by brackets 135. Obviously, other types of supports are alsofeasible.

In FIG. 3, LSHX 110 is located at a bottom of compressor 120. LSHX 110and compressor 120 are connected by single unitary pipe 127. Preferably,LSHX 110 is housed or at least partially housed within base 111 thatalso supports compressor 120. Base 111 facilitates the assembly processand provides protection from damage to various components of integralmodule 150. For instance, as shown in FIG. 3, a thermal insulation 113may be required for LSHX 110 to improve its performance. Insulation 113will be better protected while having less exposure to various externalfactors. Additionally, locating LSHX110 on a top or at a bottom ofcompressor 120 may provide better balanced position for the center ofgravity for integral module 150. This could be beneficial duringassembly and may eliminate extra brackets or a supporting structure.These examples are meant to be illustrative of the various connectionsthat can be made between LSHX 110 and compressor 120 in forming integralmodule 150.

In further embodiments, integral module 150 can include a plurality ofcompressors 120 and LSHXs 110, if a specific configuration is demandedby refrigerant system design requirements. Consequently, during designtime of a given refrigerant system, space for module 150, whichcomprises a combination of LSHXs 110 and compressors 120, is to beappropriately allocated.

Turning now to FIG. 4, illustrated is an integral module 177 including acompression system comprising two compressors 151 and 152 connected intandem and a single LSHX 110. Each compressor has suction port 125 anddischarge port 135. Suction ports 125 are connected to a suctionmanifold (or unitary pipe) 127 leading from LSHX 110. Discharge ports135 are connected into a discharge manifold 136, now representing a partof a vapor refrigerant interface. Obviously, more than two compressorscan be connected in tandem within integral module 177. Also, asdescribed below in FIG. 5, individual components of integral module 177,and compressors 151 and 152 in particular, are preferably positioned ona common base.

Turning now to FIG. 5, illustrated is an integral module 187, preferablypositioned on a common base 194 and consisting of two sub-modules 185and 186. Each sub-module has its own combination of a compressor andLSHX. In particular, sub-module 185 includes compressor 191 and LSHX 181and sub-module 186 comprises compressor 193 and LSHX 183. In otherwords, within module 187 each compressor is connected to its own LSHX.It has to be noted that vapor and liquid refrigerant interfaces eachconsist of four pairs of connections. In particular, a liquidrefrigerant interface comprises a pair of connections 130 to a condenseroutlet (or outlets) and a pair of connections 131 to an expansion deviceinlet (or inlets). Further, a vapor refrigerant interface comprises apair of connections 115 to an evaporator outlet (or outlets) and a pairof discharge ports 135 associated with compressors 191 and 193. Eachcompressor-LSHX sub-module has its own interconnecting unitary pipe 127.Also, it has to be noted that sub-modules 185 and 186 within integralmodule 187 can be connected differently, depending on the overallrefrigerant system configuration. In case, the refrigerant system hastwo-circuit configuration, each sub-module is interfaced with its owncondenser, evaporator and expansion device. On the contrary, if therefrigerant system comprises a single circuit, sub-modules 185 and 186are manifolded together, similar to a FIG. 4 exhibit. A particularpiping arrangement can be performed at the factory during manufacturingof integral module 187 or an entire refrigerant system or in the fieldduring refrigerant system installation. Obviously, integral module 187can include more than two sub-modules.

Turning to FIG. 6, illustrated is one embodiment of a refrigerant system200 that employs integral module 150. Refrigerant system 200 includesintegral module 150, a first refrigerant heat exchanger 205, anexpansion device 210, and a second refrigerant heat exchanger 215. Inthis illustrated embodiment, first refrigerant heat exchanger 205 is anevaporator, and second refrigerant heat exchanger 215 is a condenser.

Expansion device 210 is connected through connection 131 of a liquidrefrigerant interface to module 150. First refrigerant heat exchanger205 is connected through connection 115 of the vapor refrigerantinterface to integral module 150. First refrigerant heat exchanger 205is also connected to an outlet of expansion valve 210.

Second refrigerant heat exchanger 215 is connected through connection130 to module 150. Second refrigerant heat exchanger 215 is alsoconnected through discharge port 135 of the vapor refrigerant interfaceto integral module 150.

By having LSHX 110 and compressor 120 connected as integral module 150that is a separate module within system 200, installation cost andupkeep (e.g., storage and shipping costs) can be reduced. Also, a numberof manufacturing defects during assembly can be decreased. This becomespossible, since the vapor refrigerant interface (connections 115 and135) and the liquid refrigerant interface (connections 130 and 131) canbe precisely defined, since there are no further components to beinserted between LSHX 110 and compressor 120. Therefore, there is aneasier and more straightforward installation when coupling first heatexchanger 205, expansion valve 210, and second heat exchanger 215.

It should be understood that various alternatives, combinations andmodifications of the teachings described herein could be devised bythose skilled in the art. The present invention is intended to embraceall such alternatives, modifications and variances that fall within thescope of the appended claims.

1. A refrigeration apparatus (100), comprising: a liquid suction heatexchanger (LSHX) (110); and a compressor (120), wherein said LSHX (110)and said compressor (120) comprise an integral module (150).
 2. Therefrigeration apparatus (100) of claim 1, wherein said integral module(150) has a vapor refrigerant interface (115).
 3. The refrigerationapparatus (100) of claim 1, wherein said integral module (150) has aliquid refrigerant interface (130, 131).
 4. The refrigeration apparatus(100) of claim 2, wherein said vapor refrigerant interface (115, 135)has a plurality of connections (115, 135).
 5. The refrigerationapparatus (100) of claim 3, wherein said liquid refrigerant interface(130, 131) has multiple connections (130, 131).
 6. The refrigerationapparatus (100) of claim 1, further comprising a suction port connection(125) interposed between said LSHX (110) and said compressor (120). 7.The refrigeration apparatus (100) of claim 6, wherein said suction portconnection (125) is defined at least in part by a single unitary pipe(127), said unitary pipe (127) connected to both said LSHX (110) andsaid compressor (120).
 8. The refrigeration apparatus (100) of claim 7,wherein said single unitary pipe (117) contains said suction portconnection (125) at a time of manufacture of said integral module (150).9. The refrigeration apparatus (100) of claim 1, wherein said LSHX (110)is secured to said compressor (120).
 10. The refrigeration apparatus(100) of claim 1, wherein said LSHX (110) is permanently connected to asurface selected from the group consisting of a side of said compressor(120), a bottom of said compressor (120), and a top of said compressor(120).
 11. A refrigeration system (200), comprising: a condenser (215);an evaporator (205); an expansion device (210); and an integral module(150), comprising: a liquid suction heat exchanger (LSHX) (110); and acompressor (120) secured to said LSHX (110), wherein said integralmodule (150) is connected to said condenser (215), said evaporator (205)and said expansion device (210).
 12. The refrigeration system (200) ofclaim 11, wherein said integral module (150) has a vapor refrigerantinterface (115, 135).
 13. The refrigeration system (200) of claim 11,wherein said integral module (150) has a liquid refrigerant interface(130, 131).
 14. The refrigeration system (200) of claim 11, wherein saidcompressor (120) is secured to said LSHX (110) by a unitary pipe (127)that is secured to both an outlet of said LSHX (110) and an inlet ofsaid compressor (120).
 15. The refrigerant system (200) of claim 11,wherein said LSHX (110) of said integral module (150) is bolted to saidcompressor (120) of said integral module (150).
 16. The refrigerationsystem (200) of claim 11, wherein said integral module (150) furthercomprises a base (111) connected to a bottom of said compressor (120),and wherein said LSHX (110) is connected to said bottom of saidcompressor (120) and at least partially housed by said base (111). 17.The refrigeration system (200) of claim 11, wherein said integral module(150, 177) further comprises a plurality of compressors (151, 152)connected in tandem.
 18. The refrigeration system (200) of claim 11,wherein said integral module (187) is positioned on a base (194), andwherein said integral module (187) comprises a plurality of sub-modules(185, 186).
 19. The refrigeration system (200) of claim 18, wherein eachof said plurality of sub-modules (185, 186) comprises a compressor (191,193) and a LSHX (181, 183).
 20. A refrigerant system (100, 200) asherein before described with reference to any one of FIGS. 1 through 6of the accompanying drawings.